There is a user who had 3 spam post. That user is not deleted...should it be deleted? If that's the case how should we report or flag this user or similar users.
Only moderators can destroy user accounts. In this case, since the posts have been flagged as spam from enough users, no moderator did anything to delete the posts (which were automatically deleted), or delete the spam account (as no moderator noticed the spam flags).
That's fine. If the spammer writes other spam messages, it will be caught from a moderator. Apart from flagging spam as spam, there is nothing else that needs to be done.
In this case, I have already destroyed the spammer account.